This invention relates to a lighting system which enables elongate lengths of illumination to be provided for a wide range of decorative, safety and other applications.
Linear lighting systems used hitherto have generally been in the form of extruded tubing of a resilient, translucent or transparent material, e.g. extruded plastics tubing. The tubing is illuminated by a series of bulbs connected together by electric wiring to form an elongate lighting string which is threaded through the tubing to provide an internal illumination means therefor. The tubular strip is then located where desired to provide an elongate lighting system for decorative or safety purposes. For example, a length of such illuminated tubing may be provided in a non-slip nosing across the front edges of the steps of a staircase. The lighting system may be used in flooring systems e.g. at a junction between different types of flooring or floor covering. It may be provided as a decorative embellishment e.g. on walls, or display systems, or along bar pelmets, wherever a decorative pencil-line of light is desired. When resilient tubing is used, the lighting system may follow nonlinear paths, e.g. wound as a shallow spiral around columns or pillars.
However these previously known systems have certain technical and practical disadvantages. First of all, a length of the wiring incorporating the spaced apart illuminating elements does not provide a standard predictable length thereof owing to the flexibility of the wire connectors of the illuminating device which are soldered to the intermediate lengths of connecting wiring. Over a relatively long stretch there can be a very significant expansion or contraction of a supplied length of the illumination wiring resulting in a discrepancy with the length over which the illumination is required to extend. The illumination wiring which is usually stored on a roll, is relatively brittle owing to the soldered wire connectors associated with the illuminating devices, which are free to bend.
In practice, it is necessary to measure up on site the required extent of the linear illumination and then to order the required length which is cut by the supplier from a storage roll thereof. As stated above, the length when fitted on site may not match the requirement due to expansion or contraction of the supplied length. Moreover electrical connections have to be made on site, e.g. by soldering, to incorporate resistors in the system to control the voltage supplied to the illuminating devices, and to connect voltage supply lines, as well as to make any other necessary circuit connections.
U.S. Pat. No. 4,654,765 teaches an elongate lighting assembly which can be produced from insulated strips having electrical conductors thereon. The light bulbs are connected in parallel between the voltage supply lines. This specification is concerned with a method of mounting the bulbs on the strips in an easily replaceable fashion. This system therefore utilizes an entirely parallel arrangement of the light bulbs on a set of similar length strips so that the full supply voltage is applied to each light bulb, which in some applications prevents the use of relatively low voltage bulbs. Moreover it may be necessary to sever one or more of the strips to accommodate required lengths of illumination and then to electrically and mechanically connect the severed portions which can be relatively cumbersome on site.
U.S. Pat. No. 4,607,317 discloses connectors for connecting together elongate lighting circuits to form a linear strip. However each module is of the same length and requires to be cut at specific marks in order to tailor the lighting assembly to specific requirements. This limits the particular lengths which can be accommodated and makes for a relatively cumbersome procedure on site.
U.S. Pat. No. 3,755,663 discloses a display device comprising miniature lamps connected in series to form substrings which are coupled in parallel between a pair of parallel supply conductors. This assembly is then slidably inserted in a transparent flexible tube. The tube can be cut as desired but only between the substrings. This again limits the particular lengths which can be accommodated and the overall system is relatively cumbersome to assemble and to adapt to specific requirements on site.